1. Field of the Invention
The present invention relates to a magnetic attraction-fixing assembly, and more particularly, to a magnetic attraction-fixing assembly having an inner magnetic component and at least one outer magnetic component around the inner magnetic component, and the polarities of the adjacent magnetic components are opposite to each other. The present invention also relates to a rotating support structure for a portable device having the magnetic attraction-fixing assembly as an attracting and rotating component.
2. Description of the Prior Art
For the convenience in portability or to protect the tablet PC, a user usually buys a protective cover to cover the tablet PC. However, when the tablet PC is put into the protective cover, the increased weight will become a burden to the user's hands. A quickly removable protective cover is thus needed.
As shown in FIG. 25, a circular and flat magnet 70 of the prior art has a south pole at one side and a north pole at the other side. As shown in FIG. 26, the rotating and removable support structure of the portable device has a protective cover body 80 and a cover body 90, and the protective cover body 80 includes a retaining tab 81 having a first circular magnetic component 811 and a first buckle 812. The portable device is put into the back side of the cover body 90, which has a second circular magnetic component 91 and a second buckle 92, wherein the second circular magnetic component 91 attracts the first circular magnetic component 811, and the second buckle 92 buckles to the first buckle 812. The portable device placed in the protective cover body 80 can be rotated, and the protective cover body 80 and the cover body 90 can be separated depending on the user's need.
However, in the above prior art as shown in FIG. 26, the magnetic structure does not consider the properties of magnetic field lines. The circular magnetic components can hardly provide a magnetic attraction force for radial positioning, so that the first buckle 812 and the second buckle 92 are implemented in order to prevent the cover body 90 from radial sliding and detaching from the protective cover body 80 when the first circular magnetic component 811 attracts the second circular magnetic component 91. This approach will increase thickness and weight of the protective cover body 80 and the cover body 90; however, the protective cover body 80 and the cover body 90 are still prone to risk of separation.
FIG. 27 shows another conventional magnetic component commonly used on bags or clothes. In order to solve the problem that the circular magnetic component cannot provide the radial positioning, the middle of a first magnetic component 98 is usually milled with a groove 981 and the middle of a second magnetic component 99 has a tenon 991 fitted to the groove 981 of the first magnetic component 98 when attracted to each other for increasing the stability of radial positioning. But, either the groove 981 milled at the first magnetic component 98 or the tenon 991 mounted to the second magnetic component 99 will increase the thickness of the magnetic components. Therefore, the prior art still has disadvantages to be solved.
Another conventional way of magnetic enhancement is known to arrange magnets of opposite polarities in matrix. For example, a circular or rectangular magnet combination might be split in four quadrants and each quadrant is composed of a magnet with polarity opposite to its adjacent magnets. However, such type of magnet combination are still weak in lateral attraction when it comes to two magnetic combinations attracting with each other. Additionally, it also takes too much work putting these four quadrants of magnets into one.